The English language is notorious for borrowing words from other languages. And sometimes it borrows them more than once.
Historically speaking, the English language descended from Anglo Saxon (commonly called Old English). This West Germanic ancestor language formed from the tongues of the Angles, Saxons, and Jutes who entered Britain in the 5th century CE. But today, perhaps a quarter of modern English vocabulary comes from those sources. The rest, the vast majority of all the words in English, have been absorbed into the language in the last ten centuries. English is a borrowed tongue.
The most common source of English words is, of course French. France is close, geographically and historically. William the Conqueror’s Norman invasion in 1066 brought a whole host of Norman French words into English. With the subsequent ebbs and flows in Anglo-French relations over centuries, other varieties of French also entered the language, most prominently Parisian French. But this created a very curious linguistic phenomenon: sometimes a French word was borrowed into English more than once. These are the doublets.
The most famous doublet is “cattle” and “chattel.” Both came from French, the former Norman French and the latter Parisian French, and in modern English they have quite different meanings. But the distinction between these two words doesn’t exist in French – they are literally the same word. (And, by the way, both share an ultimate origin with Latin “capitāle,” which is where we get the word “capital” from as well.)
“Cattle” / “chattel” is not an exception: there are dozens of English doublets. “Guarantee” and “warranty.” “Discrete” and “discreet.” “Hostel” and “hotel.” “Cave” and “cavern.” “Cloak” and “clock” (because a cloak balloons out like a bell, apparently). “Custom” and “costume.” “Frail” and “fragile.” If you dig back even further into word histories you find the same word coming to English via multiple different intermediary languages. From a few seed words, a whole vocabulary can flourish.